Preparation of polylactide‐based microspheres enclosing acetamiprid and evaluation of efficacy against cotton aphid by soil application

Abstract

Concern for the environment has increased interest in reducing the amount of pesticides applied to agricultural land. This can be accomplished by immobilization of the pesticides in polymer supports, which prevents volatilization, degradation and leaching losses, and provides controlled release of the pesticides. In the present study, acetamiprid, a novel pesticide, was enclosed in polylactide (PLA)-based microspheres using solvent evaporation method via oil-in-oil (O/O) emulsion. Amount of acetamiprid released from PLA microspheres was less than 5% in phosphate buffered saline. On the other hand, incorporation of water-soluble polymer, such as poly(ethylene glycol) (PEG) and poly(oxyethylene) diglycolic acid, into the PLA microspheres resulted in increased amount of released acetamiprid ( 70%). Planting hole application by greenhouse pot test demonstrated that the efficacy of the PLA/PEG microspheres enclosing acetamiprid against cotton aphids was superior to that of PLA microspheres enclosing acetamiprid.

Low Molecular Weight Poly(lactic acid) Microparticles for Controlled Release of the Herbicide Metazachlor: Preparation, Morphology, and Release Kinetics

“…Similar phenomenon has been already observed with a lipophilic drug encapsulated in PLA matrix. 18 Particle diameters were controlled by ultrasonication parameters, stirring speed, and use of auxiliary surfactant Tween20 in the case of L series. Finally, S series of particles differed from M series by only about 200 nm, whereas L series particles were about 10 times larger.…”

PLAGA-PEG-PLAGA Terpolymer-Based Carriers of Herbicides for Potential Application in Environment-Friendly, Controlled Release Systems of Agrochemicals

“…Values of assumed and experimental percentage of herbicides in microspheres are presented in Table 1. The reason why PLA, PLGA and PLGA-PEG were chosen to prepare microspheres containing herbicides was that these biodegradable polymers are widely used as carriers of drugs with various targets in the pharmaceutical industry and also for some agrochemicals [29][30][31][32][33][34][35][36]. As demonstrated in previous studies [26], the presence of even a small amount of PEG block in the terpolymer chain increases the hydrophilicity of the polymeric chain slightly, thereby increasing its susceptibility to hydrolytic and-unexpectedly strongly-enzymatic degradation in the soil environment.…”

Preparation and characterisation of poly(butylene succinate) microcarriers containing pesticide

“…Both biological and chemical pesticides were achieved by encapsulation into starch matrices [18]. Researchers subsequently developed coating methods under different reaction conditions [19, 20]. Li and Xu [21] developed porous hollow silica nanoparticles synthesised by direct coating of inorganic nano‐templates, as a novel controlled release carrier for controlled drug delivery.…”